Across the various editor windows for your Static and Skeletal Meshes, you can now setup your own preview scenes to be used when inspecting your assets. This enables you to quickly assess what your assets would look like in multiple environments and lighting scenarios without having to set up these scenes within your level.
The Preview Scene Settings panel enables you to adjust the following in your preview scene:
Directional Lights: Color, Intensity, and Rotation
Sky Lights: HDRI Environment Map, Intensity, and Rotation
Post Process Volumes: All Settings